Comparitive performance of in-house RT-PCR for NSP4 gene with a commercial enzyme immunoassay for the detection of rotavirus in stool samples of children with diarrhoea

2015 ◽  
Vol 4 (6) ◽  
pp. 336-338
Author(s):  
Shilpi Srivastava ◽  
Amita Jain ◽  
Shally Awasthi ◽  
Mastan Singh
Keyword(s):  
Predictive Value ◽  
Acute Diarrhoea ◽  
Laboratory Diagnosis ◽  
Watery Diarrhoea ◽  
Nsp4 Gene ◽  
Structural Protein ◽  
Rt Pcr ◽  
Immuno Assay ◽  
Commercial Enzyme Immunoassay ◽  
Enzyme Immuno Assay

  Rotaviruses are the most significant pathogen in the etiology of watery diarrhoea in infants and young children all over the world. Laboratory diagnosis is important both for clinical management and estimation of the disease bur-den. We collected faecal samples from 260 children under the age of five years hospitalized with acute diarrhoea and tested them for rotavirus anti-gen by Enzyme immuno assay (EIA) kit [RIDASCREEN]. RNA was also extract-ed from supernatant of 10% stool suspensions in Phosphate Buffered Saline (PBS) and amplified by Reverse transcriptase polymerase chain reaction (RT-PCR) for Non Structural Protein 4 (NSP4) gene. EIA was positive in 58(22.3%) samples while RT-PCR was positive in 45(17.3%) samples. Compared to EIA, RT-PCR was 77.5% sensitive and 100% specific. The Positive Predictive Value (PPV) and Negative Predictive Value (NPV) were 100% and 93.9% respective-ly. We infer that RT-PCR is a moderately sensitive but highly specific diagnos-tic test for rotavirus infection in this study.

scholarly journals Methods for Molecular Surveillance of Influenza Used in Macedonia

PRILOZI ◽  
2014 ◽  
Vol 35 (2) ◽  
pp. 25-30
Author(s):  
Golubinka Bosevska ◽  
Elizabeta Janceska ◽  
Gordana Kuzmanovska ◽  
Vladimir Mikik ◽  
Nikola Panovski
Keyword(s):  
Influenza Virus ◽  
Predictive Value ◽  
Influenza A ◽  
Rna Extraction ◽  
Influenza Virus Infection ◽  
Laboratory Diagnosis ◽  
Influenza Viruses ◽  
Rt Pcr ◽  
Two Samples ◽  
Nose And Throat

AbstractThe aim: To present and compare different Nucleic Acid Testing assays used for laboratory diagnosis of influenza virus infection in our country.Materials and methods: Respiratory samples used were nose and throat swabs. The RNA extraction was performed with a QIAamp viral RNA kit. During the season 2009–2010 the first 25 samples were tested with: conventional gel-based RT-PCR and CDC rtRT-PCR using published specific matrix and HA gene primers and probes for influenza virus typing and subtyping.Results: Of 25 samples tested with conventional RT-PCR7(28%) were positive for influenza A, but negative for A/H1seasonal and A/H3. Retested with rtRT-PCR 9(36%) were positive for influenza A, 8(32%) were positive for A/H1pdm and 1(4%) was A/H3. Two samples positive with rtRT-PCR for influenza A were negative with RT-PCR. The sensitivity of the RT-PCR in comparison with rtRT-PCR is 100% and the specificity is 88.89%. Positive predictive value for RT-PCR is 77.78%, and negative predictive value is 100%. RT-PCR is a four-step and rtRT-PCR a one-step procedure. The turn-around time of RT-PCR is 6 hours and for rtRT-PCR it is 2 hours.Discussion and conclusion: For surveillance purposes nose and throat swabs are the more easy and practical to collect. It was proved that RT-PCR is too laborious, multi-step and time-consuming. The sensitivity of both assays is equal. The specificity of rtRT-PCR is higher. NAT assays for detection of influenza viruses have become an integral component of the surveillance programme in our country. They provide a fast, accurate and sensitive detection of influenza.

scholarly journals A Low-Cost SARS-CoV-2 rRBD ELISA to Detect Serostatus in Ecuadorian Population with COVID-19

2021 ◽  
Vol 104 (4) ◽  
pp. 1513-1515 ◽  
Author(s):  
Ángel Guevara ◽  
Sandra Vivero ◽  
Victoria Nipaz ◽  
Victor Guaraca ◽  
Josefina Coloma
Keyword(s):  
Immune Responses ◽  
Predictive Value ◽  
Intestinal Parasites ◽  
Low Cost ◽  
Laboratory Diagnosis ◽  
Igg Antibodies ◽  
Rt Pcr ◽  
Serological Tests ◽  
Simple Alternative ◽  
Sensitivity Specificity

ABSTRACTLaboratory diagnosis of the COVID-19 relies on RT-PCR to amplify specific fragments of SARS-CoV-2 genome. However, serological tests are required to determine the immune response elicited after infection. Here, we analyzed convalescent sera collected from positive individuals by RT-PCR to SARS-CoV-2 (n = 78), Zika (n = 20), dengue (n = 20), chikungunya (n = 54), intestinal parasites (n = 11), and HIV (n = 1), from different areas of Ecuador, with an in-house ELISA using a SARS-CoV-2 receptor binding domain recombinant (rRBD) antigen to detect IgG antibodies elicited by SARS-CoV-2 infection. Of the 78 samples positive for SARS-CoV-2 by RT-PCR, 73 showed high absorbance value compared with the cutoff and five were negative. All tested sera from other infections showed no reactivity. Sensitivity, specificity, positive predictive value, and negative predictive value were 93.6%, 100%, 100%, and 95.4%, respectively. This in-house anti-IgG rRBD ELISA offers an economic and simple alternative to determine IgG immune responses after SARS-CoV-2 infection.

Application of EM to differentiate herpes virus from pox virus in genital specimens

1994 ◽  
Vol 52 ◽  
pp. 262-263
Author(s):  
K. Rekrut ◽  
K. Schleuter
Keyword(s):  
Tissue Culture ◽  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Fresh Tissue ◽  
Culture Cells ◽  
Viral Transport ◽  
Carbon Coated ◽  
Immuno Assay ◽  
Simplex Virus ◽  
Enzyme Immuno Assay

Confirmation of herpes simplex virus (HSV) from genital lesions of obstetrical (OB) patients may affect both the management of the delivery and of the neonate.(l,2) During 1992 and 1993, 4,450 genital specimens from OB patients were submitted in viral transport media for herpes culture. The specimens were inoculated into MRC-5, Vero, and A-549 tissue culture tubes, incubated, and examined daily for 7 days for cytopathic effect (CPE). The original specimens were frozen at −70° C until final reports were issued. Culture tubes with CPE were tested by the Dupont Herpchek enzyme immuno assay (EIA) to confirm the presence of herpes simplex virus (HSV). (3,4) 170 OB patient specimens were positive by culture and confirmed by EIA.There were also 63 cultures exhibiting CPE ressembling HSV which were negative by EIA testing, which failed to pass in fresh tissue culture cells or progress to more enhanced CPE in culture. These original specimens were screened by electron microscopy after direct ultracentrifugation employing the Beckman airfuge with the EM 90 rotor on to formvar carbon-coated 300 mesh copper grids and negatively stained with 2% PTA.

11-dehydro-thromboxane B2 enzyme immuno assay, a suitable screening assay for aspirin use?

2001 ◽  
Vol 120 (5) ◽  
pp. A596-A596
Author(s):  
M LEERDAM ◽  
F HUDIG ◽  
W ROOIJEN ◽  
E SLAATS ◽  
A GERAEDTS ◽  
...  
Keyword(s):  
Thromboxane B2 ◽  
Screening Assay ◽  
Immuno Assay ◽  
Enzyme Immuno Assay

Screening for haemorrhagic disorders in paediatric patients by means of a questionnaire

2009 ◽  
Vol 29 (S 01) ◽  
pp. S87-S89 ◽  
Author(s):  
I. Music ◽  
M. Novak ◽  
B. Acham-Roschitz ◽  
W. Muntean
Keyword(s):  
Predictive Value ◽  
Laboratory Diagnosis ◽  
Von Willebrand Disease ◽  
Control Group ◽  
Older Children ◽  
Mild Disease ◽  
History Of ◽  
Von Willebrand ◽  
Specific Symptoms ◽  
Infants And Young Children

SummaryAim: In children, screening for haemorrhagic disorders is further complicated by the fact that infants and young children with mild disease in many cases most likely will not have a significant history of easy bruising or bleeding making the efficacy of a questionnaire even more questionable. Patients, methods: We compared the questionnaires of a group of 88 children in whom a haemorrhagic disorder was ruled out by rigorous laboratory investigation to a group of 38 children with mild von Willebrand disease (VWD). Questionnaires about child, mother and father were obtained prior to the laboratory diagnosis on the occasion of routine preoperative screening. Results: 23/38 children with mild VWD showed at least one positive question in the questionnaire, while 21/88 without laboratory signs showed at least one positive question. There was a trend to more specific symptoms in older children. Three or more positive questions were found only in VWD patients, but only in a few of the control group. The question about menstrual bleeding in mothers did not differ significantly. Sensitivity of the questionnaire for a hemostatic disorder was 0.60, while specifity was 0.76. The negative predictive value was 0.82, but the positive predictive value was only 0.52. Conclusions: Our small study shows, that a questionnaire yields good results to exclude a haemostatic disorder, but is not a sensitive tool to identify such a disorder.

scholarly journals Detection of diarrhoea associated rotavirus and co-infection with diarrhoeagenic pathogens in the Littoral region of Cameroon using ELISA, RT-PCR and Luminex xTAG GPP assays

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Rahinatou N. Ghapoutsa ◽  
Maurice Boda ◽  
Rashi Gautam ◽  
Valantine Ngum Ndze ◽  
Akongnwi E. Mugyia ◽  
...  
Keyword(s):  
Demographic Data ◽  
Laboratory Diagnosis ◽  
Epidemiological Studies ◽  
Sub Saharan Africa ◽  
Rt Pcr ◽  
Mortality And Morbidity ◽  
Vaccine Introduction ◽  
Littoral Region ◽  
Rotavirus Vaccines ◽  
The Impact

Abstract Background Despite the global roll-out of rotavirus vaccines (RotaTeq/Rotarix / ROTAVAC/Rotasiil), mortality and morbidity due to group A rotavirus (RVA) remains high in sub-Saharan Africa, causing 104,000 deaths and 600,000 hospitalizations yearly. In Cameroon, Rotarix™ was introduced in March 2014, but, routine laboratory diagnosis of rotavirus infection is not yet a common practice, and vaccine effectiveness studies to determine the impact of vaccine introduction have not been done. Thus, studies examining RVA prevalence post vaccine introduction are needed. The study aim was to determine RVA prevalence in severe diarrhoea cases in Littoral region, Cameroon and investigate the role of other diarrheagenic pathogens in RVA-positive cases. Methods We carried out a study among hospitalized children < 5 years of age, presenting with acute gastroenteritis in selected hospitals of the Littoral region of Cameroon, from May 2015 to April 2016. Diarrheic stool samples and socio-demographic data including immunization and breastfeeding status were collected from these participating children. Samples were screened by ELISA (ProSpecT™ Rotavirus) for detection of RVA antigen and by gel-based RT-PCR for detection of the VP6 gene. Co-infection was assessed by multiplexed molecular detection of diarrheal pathogens using the Luminex xTAG GPP assay. Results The ELISA assay detected RVA antigen in 54.6% (71/130) of specimens, with 45, positive by VP6 RT-PCR and 54, positive using Luminex xTAG GPP. Luminex GPP was able to detect all 45 VP6 RT-PCR positive samples. Co-infections were found in 63.0% (34/54) of Luminex positive RVA infections, with Shigella (35.3%; 12/34) and ETEC (29.4%; 10/34) detected frequently. Of the 71 ELISA positive RVA cases, 57.8% (41/71) were fully vaccinated, receiving two doses of Rotarix. Conclusion This study provides insight on RVA prevalence in Cameroon, which could be useful for post-vaccine epidemiological studies, highlights higher than expected RVA prevalence in vaccinated children hospitalized for diarrhoea and provides the trend of RVA co-infection with other enteric pathogens. RVA genotyping is needed to determine circulating rotavirus genotypes in Cameroon, including those causing disease in vaccinated children.

scholarly journals Triage of Patients Suspected of COVID-19 in Chronic Hemodialysis: Eosinophil Count Differentiates Low and High Suspicion of COVID-19

2020 ◽  
Vol 10 (1) ◽  
pp. 4
Author(s):  
Romain Vial ◽  
Marion Gully ◽  
Mickael Bobot ◽  
Violaine Scarfoglière ◽  
Philippe Brunet ◽  
...  
Keyword(s):  
Predictive Value ◽  
Eosinophil Count ◽  
Characteristic Curve ◽  
Final Analysis ◽  
Hemodialysis Patients ◽  
Chronic Hemodialysis ◽  
Screening Methods ◽  
Dialysis Session ◽  
Diagnostic Study ◽  
Rt Pcr

Background: Daily management to shield chronic dialysis patients from SARS-CoV-2 contamination makes patient care cumbersome. There are no screening methods to date and a molecular biology platform is essential to perform RT-PCR for SARS-CoV-2; however, accessibility remains poor. Our goal was to assess whether the tools routinely used to monitor our hemodialysis patients could represent reliable and quickly accessible diagnostic indicators to improve the management of our hemodialysis patients in this pandemic environment. Methods: In this prospective observational diagnostic study, we recruited patients from La Conception hospital. Patients were eligible for inclusion if suspected of SARS-CoV-2 infection when arriving at our center for a dialysis session between March 12th and April 24th 2020. They were included if both RT-PCR result for SARS-CoV-2 and cell blood count on the day that infection was suspected were available. We calculated the area under the curve (AUC) of the receiver operating characteristic curve. Results: 37 patients were included in the final analysis, of which 16 (43.2%) were COVID-19 positive. For the day of suspected COVID-19, total leukocytes were significantly lower in the COVID-19 positive group (4.1 vs. 7.4 G/L, p = 0.0072) and were characterized by lower neutrophils (2.7 vs. 5.1 G/L, p = 0.021) and eosinophils (0.01 vs. 0.15 G/L, p = 0.0003). Eosinophil count below 0.045 G/L identified SARS-CoV-2 infection with AUC of 0.9 [95% CI 0.81—1] (p < 0.0001), sensitivity of 82%, specificity of 86%, a positive predictive value of 82%, a negative predictive value of 86% and a likelihood ratio of 6.04. Conclusions: Eosinophil count enables rapid routine screening of symptomatic chronic hemodialysis patients suspected of being COVID-19 within a range of low or high probability.

scholarly journals A meta-analysis of accuracy and sensitivity of chest CT and RT-PCR in COVID-19 diagnosis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Fatemeh Khatami ◽  
Mohammad Saatchi ◽  
Seyed Saeed Tamehri Zadeh ◽  
Zahra Sadat Aghamir ◽  
Alireza Namazi Shabestari ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Reverse Transcriptase ◽  
Ct Scan ◽  
Predictive Value ◽  
Meta Analysis ◽  
Chest Ct ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Chest Ct Scan

AbstractNowadays there is an ongoing acute respiratory outbreak caused by the novel highly contagious coronavirus (COVID-19). The diagnostic protocol is based on quantitative reverse-transcription polymerase chain reaction (RT-PCR) and chests CT scan, with uncertain accuracy. This meta-analysis study determines the diagnostic value of an initial chest CT scan in patients with COVID-19 infection in comparison with RT-PCR. Three main databases; PubMed (MEDLINE), Scopus, and EMBASE were systematically searched for all published literature from January 1st, 2019, to the 21st May 2020 with the keywords "COVID19 virus", "2019 novel coronavirus", "Wuhan coronavirus", "2019-nCoV", "X-Ray Computed Tomography", "Polymerase Chain Reaction", "Reverse Transcriptase PCR", and "PCR Reverse Transcriptase". All relevant case-series, cross-sectional, and cohort studies were selected. Data extraction and analysis were performed using STATA v.14.0SE (College Station, TX, USA) and RevMan 5. Among 1022 articles, 60 studies were eligible for totalizing 5744 patients. The overall sensitivity, specificity, positive predictive value, and negative predictive value of chest CT scan compared to RT-PCR were 87% (95% CI 85–90%), 46% (95% CI 29–63%), 69% (95% CI 56–72%), and 89% (95% CI 82–96%), respectively. It is important to rely on the repeated RT-PCR three times to give 99% accuracy, especially in negative samples. Regarding the overall diagnostic sensitivity of 87% for chest CT, the RT-PCR testing is essential and should be repeated to escape misdiagnosis.

scholarly journals The role of CT imaging for management of COVID-19 in epidemic area: early experience from a University Hospital

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Vikram rao Bollineni ◽  
Koenraad Hans Nieboer ◽  
Seema Döring ◽  
Nico Buls ◽  
Johan de Mey
Keyword(s):  
Ct Scan ◽  
Predictive Value ◽  
Ct Imaging ◽  
Chest Ct ◽  
University Hospital ◽  
Rt Pcr ◽  
Ct Findings ◽  
Epidemic Area ◽  
Chest Ct Scan ◽  
Pcr Test

Abstract Background To evaluate the clinical value of the chest CT scan compared to the reference standard real-time polymerase chain reaction (RT-PCR) in COVID-19 patients. Methods From March 29th to April 15th of 2020, a total of 240 patients with respiratory distress underwent both a low-dose chest CT scan and RT-PCR tests. The performance of chest CT in diagnosing COVID-19 was assessed with reference to the RT-PCR result. Two board-certified radiologists (mean 24 years of experience chest CT), blinded for the RT-PCR result, reviewed all scans and decided positive or negative chest CT findings by consensus. Results Out of 240 patients, 60% (144/240) had positive RT-PCR results and 89% (213/240) had a positive chest CT scans. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of chest CT in suggesting COVID-19 were 100% (95% CI: 97–100%, 144/240), 28% (95% CI: 19–38%, 27/240), 68% (95% CI: 65–70%) and 100%, respectively. The diagnostic accuracy of the chest CT suggesting COVID-19 was 71% (95% CI: 65–77%). Thirty-three patients with positive chest CT scan and negative RT-PCR test at baseline underwent repeat RT-PCR assay. In this subgroup, 21.2% (7/33) cases became RT-PCR positive. Conclusion Chest CT imaging has high sensitivity and high NPV for diagnosing COVID-19 and can be considered as an alternative primary screening tool for COVID-19 in epidemic areas. In addition, a negative RT-PCR test, but positive CT findings can still be suggestive of COVID-19 infection.

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